Method of controlling vectors in motor and vector-controlling inverter device

Abstract

In a vector control method for controlling a motor by detecting a primary current in a motor driven by an inverter circuit with an electric current detector, dividing the primary current detection value detected by the electric current detector to a current-for-torque detection value and a detected current-for-excitation detection value, and thus dividing a primary current instruction value to a current-for-torque instruction value and a current-for-excitation value, a portion between the current-for-torque detection value and current-for-excitation detection value each obtained from the primary current detection value is changed by an Iq gain circuit (gain Kqc) and an Id gain circuit (gain Kd), which are discrete circuits, and the rated torque characteristics of the motor is changed according to change of the apportion.

What is claimed is: 
     
       1. A method of controlling vectors in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current instruction value for excitation for controlling the motor; comprising the steps of changing an apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value and changing the rated torque characteristics of the motor according to change of the apportion. 
     
     
       2. A method of controlling vectors in a motor according to claim 1; wherein apportion between the current detection value for torque and current detection value for excitation is changed by discretely setting a gain for the current detection value for torque and the current detection value for excitation. 
     
     
       3. A method of controlling vectors in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current instruction value for excitation for controlling the motor; comprising the steps of changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to an external input signal and switching the rated torque characteristics of the motor according to change of the apportion. 
     
     
       4. A method of controlling vectors in a motor according to claim 3; wherein said external input signal discriminates a short time torque mode in which desired characteristics are obtained for a short time rated torque from a continuous torque mode in which desired characteristics for a continuous rated torque are obtained and the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       5. A method of controlling vectors in a motor according to claim 3; wherein the apportion between the current detection value for torque and the current detection value for excitation is changed by discretely setting a gain for the current detection value for torque and the current detection value for excitation. 
     
     
       6. A method of controlling vectors in a motor according to claim 3; wherein a PWM frequency for a pulse width modulating circuit for controlling an inverter is switched according to switching of the rated torque characteristics of the motor by means of changing the apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       7. A method of controlling vectors in a motor according to claim 6; wherein in a short time mode, the PWM frequency is set to a frequency which is lower than the frequency of the PWM frequency of an ordinary mode and wherein in a continuous torque mode, the PWM frequency is set to a frequency which is equal to the PWM frequency of the ordinary mode. 
     
     
       8. A method of controlling a vector in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current instruction value for excitation for controlling the motor; comprising the steps of detecting a converter voltage, changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to the converter voltage detection value, and switching the rated torque characteristics for the motor according to the change of apportion. 
     
     
       9. A method of controlling vectors in a motor according to claim 8; wherein a continuous torque mode in which desired characteristics for a continuous rated torque are obtained is automatically selected in a case where said converter voltage is low, a short time torque mode in which desired characteristics for a short time rated torque are obtained is automatically selected in a case where said converter voltage is high, and apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       10. A method of controlling vectors in a motor according to claim 8; wherein the apportion between the current detection value for torque and the current detection value for excitation is changed by discretely setting a gain for the current detection value for torque and the current detection value for excitation. 
     
     
       11. A method of controlling vectors in a motor according to claim 8; wherein a PWM frequency for a pulse width modulating circuit for controlling an inverter is switched according to switching of the rated torque characteristics of the motor by means of changing apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       12. A method of controlling vectors in a motor according to claim 11; wherein in a short time mode, the PWM frequency is set to a frequency which is lower than the frequency of the PWM frequency of an ordinary mode and wherein in a continuous torque mode, the PWM frequency is set to a frequency which is equal to the PWM frequency of the ordinary mode. 
     
     
       13. A method of controlling a vector in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current instruction value for excitation for controlling the motor; comprising the steps of making a determination as to whether the motor is in powering mode or in regeneration mode, changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to whether the motor is in powering mode or in regeneration mode, and switching the rated torque characteristics for the motor according to the change of the apportion. 
     
     
       14. A method of controlling vectors in a motor according to claim 13; wherein it is determined that the motor is in regeneration mode if a product of multiplication between a speed detection value for the motor and the current detection value for torque is negative and that the motor is in powering mode if the product is positive. 
     
     
       15. A method of controlling vectors in a motor according to claim 13; wherein a continuous torque mode in which desired characteristics for a continuous rated torque are obtained is automatically selected in a case of the powering mode, a short time torque mode in which desired characteristics for a short time rated torque are obtained is automatically selected in a case of the regeneration mode, and apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       16. A method of controlling vectors in a motor according to claim 13; wherein apportion between the current detection value for torque and the current detection value for excitation is changed by discretely setting a gain for the current detection value for torque and the current detection value for excitation. 
     
     
       17. A method of controlling vectors in a motor according to claim 13; wherein a PWM frequency for a pulse width modulating circuit for controlling an inverter is switched according to switching of the rated torque characteristics of the motor by means of changing apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       18. A method of controlling vectors in a motor according to claim 17; wherein in a short time mode, the PWM frequency is set to a frequency which is lower than the frequency of the PWM frequency of an ordinary mode and wherein in a continuous torque mode, the PWM frequency is set to a frequency which is equal to the PWM frequency of the ordinary mode. 
     
     
       19. A method of controlling a vector in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current instruction value for excitation for controlling the motor; comprising the steps of making a determination as to whether or not the inverter circuit is accelerated/decelerated, changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to whether or not the inverter circuit is accelerated/decelerated and switching the rated torque characteristics of the motor according to the change of apportion. 
     
     
       20. A method of controlling vectors in a motor according to claim 19; wherein it is determined that the inverter circuit is accelerated/decelerated in a case where an absolute value of deviation between an speed instruction value and a speed detection value is not less than a specified value and that the inverter circuit is not accelerated/decelerated in a case where an absolute value of deviation between the speed instruction value and the speed detection value is less than the specific value. 
     
     
       21. A method of controlling vectors in a motor according to claim 19; wherein a continuous torque mode in which desired characteristics for a continuous rated torque are obtained is automatically selected in a case where the inverter circuit is not accelerated/decelerated, a short time torque mode in which desired characteristics for a short time rated torque are obtained is automatically selected in a case where the inverter circuit is accelerated/decelerated, and apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       22. A method of controlling vectors in a motor according to claim 19; wherein apportion between the current detection value for torque and the current detection value for excitation is changed by discretely setting a gain for the current detection value for torque and the current detection value for excitation. 
     
     
       23. A method of controlling vectors in a motor according to claim 19; wherein a PWM frequency for a pulse width modulating circuit for controlling an inverter is switched according to switching of the rated torque characteristics of the motor by means of changing apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       24. A method of controlling vectors in a motor according to claim 23; wherein in a short time mode, the PWM frequency is set to a frequency which is lower than the frequency of the PWM frequency of an ordinary mode and wherein in a continuous torque mode, the PWM frequency is set to a frequency which is equal to the PWM frequency of the ordinary mode. 
     
     
       25. A vector-controlling inverter device in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current detection value for excitation for controlling the motor; wherein said inverter device has a means for changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value and changes the rated torque characteristics for the motor according to change of the apportion. 
     
     
       26. A vector-controlling inverter device in a motor according to claim 25; wherein said means for changing the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value are gain circuits discretely provided for the current detection value for torque and for the current detection value for excitation. 
     
     
       27. A vector-controlling inverter device in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current detection value for excitation for controlling the motor; wherein said inverter device has a means for changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to an external input signal and switches the rated torque characteristics for the motor according to change of the apportion. 
     
     
       28. A vector-controlling inverter device in a motor according to claim 27; wherein said external input signal discriminates a short time torque mode in which desired characteristics for a short time rated torque are obtained from a continuous torque mode in which desired characteristics for a continuous rated torque are obtained and apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       29. A vector-controlling inverter device in a motor according to claim 27; wherein said means for changing the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value are gain circuits discretely provided for the current detection value for torque and for the current detection value for excitation. 
     
     
       30. A vector-controlling inverter device in a motor according to claim 27 comprising a PWM frequency switching instruction circuit for switching and setting a PWM frequency for a pulse width modulating circuit for inverter control according to switching of the rated torque characteristics of the motor by changing the apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       31. A vector-controlling inverter device in a motor according to claim 30; wherein, in a short time torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is lower than the PWM frequency in an ordinary mode, and wherein, in a continuous torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is equal to the PWM frequency in the ordinary mode. 
     
     
       32. A vector-controlling inverter device in a motor which operates by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current detection value for excitation for controlling the motor; wherein said inverter device comprises a converter voltage comparator for determining whether or not the converter voltage is less than a specified value and a means for changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to an output signal from the converter voltage comparator and switches the rated torque characteristics for the motor according to change of the apportion. 
     
     
       33. A vector-controlling inverter device in a motor according to claim 32; wherein, according to a result of comparison with said converter voltage comparator, a continuous torque mode in which desired characteristics for continuous rated torque are obtained is automatically selected in a case where the converter voltage is lower than said specified value, a short time torque mode in which desired characteristics for short time rated torque are obtained is automatically selected in a case where the converter voltage is higher than said specified value, and apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       34. A vector-controlling inverter device in a motor according to claim 32; wherein said means for changing the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value are gain circuits discretely provided for the current detection value for torque and for the current detection value for excitation. 
     
     
       35. A vector-controlling inverter device in a motor according to claim 32 comprising a PWM frequency switching instruction circuit for switching and setting a PWM frequency for a pulse width modulating circuit for inverter control according to switching of the rated torque characteristics of the motor by changing the apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       36. A vector-controlling inverter device in a motor according to claim 35; wherein, in a short time torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is lower than the PWM frequency in an ordinary mode, and wherein, in a continuous torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is equal to the PWM frequency in the ordinary mode. 
     
     
       37. A vector-controlling inverter device in a motor by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current detection value for excitation for controlling the motor; wherein said inverter device comprises a powering/regeneration mode determining circuit for determining whether the motor is in powering mode or in regeneration mode and a means for changing apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to a result of determination by said powering/regeneration mode determining circuit and switches the rated torque characteristics for the motor according to change of the apportion. 
     
     
       38. A vector-controlling inverter device in a motor according to claim 37; wherein said powering/regeneration mode determining circuit multiplies a speed detection value for the motor by the current detection value for torque and determines that the motor is in the regeneration mode if the product is negative and that the motor is in the powering mode if the product is positive. 
     
     
       39. A vector-controlling inverter device in a motor according to claim 37; wherein a continuous torque mode in which desired characteristics for a continuous rated torque obtained is automatically selected in a case where it is determined by said powering/regeneration mode determining circuit that the mode is in the powering mode, a short time torque mode in which desired characteristics for a short time rated torque are obtained is automatically selected in a case where it is determined by said powering/regeneration mode determining circuit that the mode is in the regeneration mode, and apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       40. A vector-controlling inverter device in a motor according to claim 37; wherein said means for changing the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value are gain circuits discretely provided for the current detection value for torque and for the current detection value for excitation. 
     
     
       41. A vector-controlling inverter device in a motor according to claim 37, further comprising a PWM frequency switching instruction circuit for switching and setting a PWM frequency for a pulse width modulating circuit for inverter control according to switching of the rated torque characteristics of the motor by changing the apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       42. A vector-controlling inverter device in a motor according to claim 41; wherein, in a short time torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is lower than the PWM frequency in an ordinary mode, and wherein, in a continuous torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is equal to the PWM frequency in the ordinary mode. 
     
     
       43. A vector-controlling inverter device in a motor which operates by detecting a primary current in the motor driven by an inverter circuit with a current detector, dividing a value for the primary current detected with said current detector to a current detection value for torque and a current detection value for excitation, and dividing an instruction value for the primary current to a current instruction value for torque and a current instruction value for excitation for controlling the motor; wherein said inverter device comprises an acceleration/deceleration determining circuit for determining whether or not the inverter circuit is in acceleration/deceleration and a means for changing the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value according to a result of determination by said acceleration/deceleration determining circuit and switches the rated torque characteristics for the motor according to change of the apportion. 
     
     
       44. A vector-controlling inverter device in a motor according to claim 43; wherein said acceleration/deceleration determining circuit determines that the inverter circuit is in acceleration/deceleration in a case where an absolute value of deviation between a speed instruction value and a speed detection value is not less than a specified value and that the inverter circuit is not in acceleration/deceleration in a case where an absolute value of deviation between the speed instruction value and the speed detection value is less than the specified value. 
     
     
       45. A vector-controlling inverter device in a motor according to claim 43; wherein a continuous torque mode in which desired characteristics for continuous rated torque are obtained is automatically selected in a case where it is determined by said acceleration/deceleration determining circuit that the inverter circuit is not accelerated/decelerated, a short time torque mode in which desired characteristics for short time rated torque are obtained is automatically selected in a case where it is determined by said acceleration/deceleration determining circuit that the inverter circuit is accelerated/decelerated, and the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value is switched between the short time torque mode and the continuous torque mode. 
     
     
       46. A vector-controlling inverter device in a motor according to claim 43; wherein said means for changing the apportion between the current detection value for torque and the current detection value for excitation obtained from said primary current detection value are gain circuits discretely provided for the current detection value for torque and for the current detection value for excitation. 
     
     
       47. A vector-controlling inverter device in a motor according to claim 43 comprising a PWM frequency switching instruction circuit for switching and setting a PWM frequency for a pulse width modulating circuit for inverter control according to switching of the rated torque characteristics of the motor by changing the apportion between the current detection value for torque and the current detection value for excitation obtained from the primary current detection value. 
     
     
       48. A vector-controlling inverter device in a motor according to claim 47; wherein, in a short time torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is lower than the PWM frequency in an ordinary mode, and wherein, in a continuous torque mode, said PWM frequency switching instruction circuit sets the PWM frequency to a frequency which is equal to the PWM frequency in the ordinary mode.